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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 13 |
| 4 | 55 |
| 5 | 183 |
| 6 | 819 |
| 7 | 2879 |
| 8 | 13213 |
| 9 | 49231 |
| 10 | 226629 |
| 11 | 876199 |
| 12 | 4067573 |
| 13 | 16096651 |
| 14 | 75181093 |
| 15 | 303273801 |
| 16 | 1421299301 |
| 17 | 5822068963 |
| 18 | 27370535379 |
| 19 | 113468717975 |
| 20 | 534935197769 |
| 21 | 2239853274431 |
| 22 | 10582195871479 |
| 23 | 44689058243777 |
| 24 | 211516425857617 |
| 25 | 899732843252239 |
| 26 | 4265497711986437 |
| 27 | 18257957134293345 |
[1,1,5,13,55,183,819,2879,13213,49231,226629, 876199,4067573,16096651,75181093,303273801, 1421299301,5822068963,27370535379,113468717975, 534935197769,2239853274431,10582195871479, 44689058243777,211516425857617,899732843252239, 4265497711986437,18257957134293345] |